1. Do all the guests want dessert? I don't know. I (ask) them.

2. Will you (come) over for dinner tonight? OK, I will come at 8:30 PM.

3. Why is Peter buying ski equipment? Is he going to (learn) how to ski? Yes, he is going to (take) skiing lessons at the Winter Club.

4. The weather has changed. It's very cold today. Really? I (take) a jumper with me then.

5. Oh no! Look at the fuel. We (run) out of petrol soon.

6. you (have) time to show me the sights if I come to Rome next weekend?

7. The police officer is stopping that car. He (give) the driver a ticket for speeding.

Do all the guests want dessert? I don't know. I will ask them.
- In this context, 'will ask' is used because the decision to ask is being made at the moment of speaking. The speaker decides to find out what the guests want right now.
Will you come over for dinner tonight? OK, I will come at 8.30 pm.
- 'Will you come' is a question inviting someone to an event, so the future simple tense is used. The response confirms the time with 'will come'.
Why is Peter buying ski equipment? Is he going to learn how to ski? Yes. He is going to take skiing lessons at the Winter Club.
- 'Going to learn' introduces the idea that Peter has a plan or intention to learn skiing in the future.
The weather has changed. It's very cold today. Really? I will take a jumper with me then.
- The decision to take a jumper is made at the time of speaking, so we use 'will take'.
Oh no! Look at the fuel. We are going to run out of petrol soon.
- 'Going to run' is used because it indicates a prediction based on current evidence—the fuel gauge showing low fuel.
Will you have time to show me the sights if I come to Rome next weekend?
- This question is a polite way to request or plan for future availability, so 'will have' is used.
The police officer is stopping that car. He is going to give the driver a ticket for speeding.
- 'Is going to give' shows a planned action that is expected to happen very soon based on the current situation.